This
is the first Audiolab DAC since the 8000DAC
was launched way back in 1992. In the meantime the brand has
undergone a change of ownership, has appointed a new designer, and changed the
location of production from the UK to China. One consequence is that this £599
M-DAC looks a far more
convincing commodity product than its predecessor. The aluminium case is well
finished in either black or silver, and the clear and informative display is a
nonstandard size that makes it look more mainstream commercial than boutique
audio. Not only does the display provide information about the input selection
and lock status, but it also translates the sub-code transmitted over S/PDIF
to display CD track number and time, and if required a precise read out of
input sampling frequency. A digital level meter with peak hold has an
attractive decibel read-out.

The DAC is
designed by John Westlake, who has gained a reputation for creating good
sounding and desirable products for several manufacturers over a couple of
decades. He has squeezed quite a lot of technology into this product, which
makes an interesting comparison with the main competition around at the
moment. The M-DAC has a variety
of digital filter options, which is a quite fashionable feature among
today's DACs.

I haven't got
space here to go significantly into digital filter technology but you would
think there would be one correct way to implement a digital filter. Alas when
you get one aspect just right, something else goes slightly wrong, and
designers just have to compromise, or leave it up to the user to choose from a
number of available compromises. The hardware processing power that is used to
implement the digital filter algorithms can also be used to generate a volume
function, and this is done here, but it can be deactivated should the customer
be using an integrated or pre-amplifier.

This product has
two co-axial, two optical and one USB input – all that's required to
provide preamplifier function for a multiple digital source system if no
analogue source is used. Both TosLink and coaxial digital outputs are
available, and analogue outputs are provided on both true balanced (XLR) and
single ended (RCA phono) sockets.

Inside, fully
discrete Class A analogue amplifiers using J-Fets provide a high current drive
potential with good immunity from RF demodulation. A 32-bit ESS Sabre
9018 digital-to-analogue chip is mounted on a multi-layer board,
using both throughhole and surface-mount technology. A separate board, mounted
at right angles, contains a bank of power supply reservoir capacitors.

The USB input is
asynchronous, supporting 24-bit/96kHz with remote control of PC or Mac media
players. Selected parts are used throughout with 0.1% MELF surface-mount
resistors and both polypropylene film/foil and organic ultra-low-ESR
capacitors. An external power supply keeps all the noisy bits away from the
sensitive circuitry and offers future upgrade possibilities.

Test
Results

The M-DAC's
frequency response (and also its output level on some settings) varies with
the filter settings. All the 'optimal transient' settings produced an
early treble fall, starting at 3kHz and -0.7dB at 20kHz. The 'minimum
phase' filter shows a slight rise above 15kHz, while 'optimal spectrum'
is almost flat but with a slight high frequency ripple. 'Sharp roll-off'
is flat almost all the way to 10kHz and is only 0.15dB down at 20kHz, but at
1kHz has a 0.2dB lower output as does 'slow roll-off' which is an audible
1.6dB down at 20kHz ref. 1kHz.

The jitter
spectrogram is very clean, indicating very low levels of jitter, but there is
a hint of 100Hz hum breakthrough down at -120dB. Harmonic distortion is very
low indeed and the low level linearity test shows virtually no deviation right
down to -112dB with the error value below this due to hum. When set at 0dB the
output level is an audible 1dB above the industry's standard 2V.

Sound
Quality

Using the
coaxial S/PDIF input from a Naim NDS network
player, we were quite enthusiastic about the M-DAC
on first listening. We were seduced by its fine focus and
soundstage construction, good bass weight and overall definition. The treble
was airy with fine detail and the mid was nicely articulate. It appeared quite
subtle, clean and spacious.

Next I tried the
USB input from my desktop computer, and found it lacking here in both dynamics
and timing. It was still quite spacious but dynamics lacked freedom
irrespective of the filter setting. It sounds a little restrained and just
doesn't have the full measure of dynamic expression necessary for a top
class digital replay system.

With the digital
data provided from a CD drive, it images very well and supplies a vast amount
of detail, but it still doesn't have sufficient verve to earn a place in my
own system. I played around with the filter settings, and preferred the 'slow roll-off' setting, but was still aware of an aural energy imbalance
manifest in a slightly unnerving hardness in the upper mid/lower treble region
that becomes tiring after a while. It does deliver lots of detail – more
indeed than the vast majority of its peers – and must judged very
transparent, but I still felt slightly uncomfortable by the balance of
compromises found here. While it teaches the Rega DAC
how to resolve minutiae, for example, it doesn't manage to
structure music quite as naturally. I also tried it playing some high
resolution material when connected to the Astell and Kern AK100
portable player, and although it is able to cope well with more
information, the innate character of the sound doesn't change, and the same
was true of music replayed from a memory stick, which often provides an
improvement.

Finally I went
back to where I started, connecting the M-DAC
to the reference level Naim NDS S/PDIF
feed, where we found that the M-DAC continued
to sound rather restrained over a protracted listening session. Its dynamics
are just not as convincing as the best of the current crop of DACs, and a
slight metallic sheen makes it sound larger than life, leading to the false
impression of true high end sound. Furthermore, it lacks some expressiveness,
softening and compressing both macro and micro dynamics – the 'optimal
transient' filter setting had better tonality, but sounded even softer and
had 'slowed' timing.

We tried all the
digital filters, and they do all sound different. But in one way or another
they all shift the sense of timing away from my references: the closest to
what I consider a 'normal' sound is the 'slow rolloff' setting. It's
also noticeable that some filter settings have more treble energy than others,
and these can sometimes sound a bit hard and glaring. This can add apparent
extra detail, or is that lessened less masking when sounds are thus falsely
separated?

After several
extended listening sessions, I couldn't escape the feeling that I was
listening to a more 'processed' digital replay than I was used to. I'd
freely admit that I've been listening to a lot of analogue recently, but
going back to other CD and DAC implementations that I habitually use, and
after comparison with the others under test, I have become convinced that the
Audiolab presents music a little differently. At times the M-DAC
could sound very entertaining, but I have to conclude that it never
sounds quite natural or convincingly expressed sufficient musical realism.

Conclusions

Considerable
technical expertise has been applied to make this product what it is, and from
a user point of view it's easy to get carried away, playing with the options
and enjoying the effects of the various facilities. Lots of options are
available through the menu and that rather decent remote control, but it must
be remembered that the object of any piece of hi-fi kit is to fool the
listener into thinking that the reproduction is close enough to live music to
trigger the brain into believing that what's happening in your room is truly
enjoyable, not just a cerebral exercise in hearing some extra micro-detail.

I'm sure that
all HIFICRITIC readers will know
that this state of mind varies, depending on experience and how your brain
decodes music. I rely on comparison to remembered live music experiences, and
also direct comparison with those bits of kit that I have found tend to
fulfill those musical requirements. Make no mistake, I admire the thinking and
the science that has gone into designing the M-DAC.

I like its
utility and technical perfection. I like the display and I like the
facilities. I also like the fact that it's available at a reasonable price.
However, it failed fully to excite me musically, and on certain material and
settings it even goes so far as to irritate. On balance it therefore achieves
a sound quality score of 70. It is brilliant but slightly flawed, and not to
my taste, though at this price, considering the facilities, and providing the
slightly different presentation offered is acceptable, it does offer very good
value.